/**
* Copyright (C) 2008 Happy Fish / YuQing
*
* FastDFS Java Client may be copied only under the terms of the GNU Lesser
* General Public License (LGPL).
* Please visit the FastDFS Home Page http://www.csource.org/ for more detail.
*/

package com.hlf.common.oss.fastdfs;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Socket;

/**
* Tracker server group
* @author Happy Fish / YuQing
* @version Version 1.17
*/
public class TrackerGroup
{
    protected Integer lock;
    public int tracker_server_index;
    public InetSocketAddress[] tracker_servers;

/**
* Constructor
* @param tracker_servers tracker servers
*/
    public TrackerGroup(InetSocketAddress[] tracker_servers)
    {
        this.tracker_servers = tracker_servers;
        this.lock = new Integer(0);
        this.tracker_server_index = 0;
    }

/**
* return connected tracker server
* @return connected tracker server, null for fail
*/
    public TrackerServer getConnection(int serverIndex) throws IOException
    {
        Socket sock = new Socket();
        sock.setReuseAddress(true);
        sock.setSoTimeout(ClientGlobal.g_network_timeout);
        sock.connect(this.tracker_servers[serverIndex], ClientGlobal.g_connect_timeout);
        return new TrackerServer(sock, this.tracker_servers[serverIndex]);
    }

/**
* return connected tracker server
* @return connected tracker server, null for fail
*/
    public TrackerServer getConnection() throws IOException
    {
        int current_index;

        synchronized(this.lock)
        {
            this.tracker_server_index++;
            if (this.tracker_server_index >= this.tracker_servers.length)
            {
                this.tracker_server_index = 0;
            }

            current_index = this.tracker_server_index;
        }

        try
        {
            return this.getConnection(current_index);
      }
      catch(IOException ex)
      {
          System.err.println("connect to server " + this.tracker_servers[current_index].getAddress().getHostAddress() + ":" + this.tracker_servers[current_index].getPort() + " fail");
          ex.printStackTrace(System.err);
      }

      for (int i=0; i<this.tracker_servers.length; i++)
      {
          if (i == current_index)
          {
              continue;
          }

            try
            {
                TrackerServer trackerServer = this.getConnection(i);

                synchronized(this.lock)
                {
                    if (this.tracker_server_index == current_index)
                    {
                        this.tracker_server_index = i;
                    }
                }

                return trackerServer;
          }
          catch(IOException ex)
          {
              System.err.println("connect to server " + this.tracker_servers[i].getAddress().getHostAddress() + ":" + this.tracker_servers[i].getPort() + " fail");
              ex.printStackTrace(System.err);
          }
      }

      return null;
    }

    public Object clone()
    {
        InetSocketAddress[] trackerServers = new InetSocketAddress[this.tracker_servers.length];
        for (int i=0; i<trackerServers.length; i++)
        {
            trackerServers[i] = new InetSocketAddress(this.tracker_servers[i].getAddress().getHostAddress(), this.tracker_servers[i].getPort());
        }

        return new TrackerGroup(trackerServers);
    }
}
